CN102782422A - Optically active multilayer system for solar absorption - Google Patents

Abstract

The invention relates to a composite material for use as a selective solar absorber having a carrier layer (1), wherein at least the following layers are present on a side (B) of the carrier layer: a reflection layer (3), an absorber layer (5), and a dielectric and/or oxidic antireflection layer (7), wherein a layer (4) made of a nitride, a carbide, or a carbonitride of a metal or a mixture of at least two metals from the subgroups IV, V, or VI is present between the absorber layer (5) and the reflection layer (3), and an optically active layer (6) made of a metal compound having stoichiometric composition is present between the absorber layer (5) and the dielectric antireflection layer (7).; The invention further relates to a composite material for use as a selective solar absorber, having a carrier layer (1) made of aluminum or an aluminum alloy, wherein an optically active layer (8) is present on one side (A) of the carrier layer, reducing the reflection of the uncoated carrier material by at least 5% for a specific wavelength in the wavelength range of 200 nm to 10[mu]m, preferably between 200 and 2500 nm, for irradiation at a specific index angle, and reducing the reflection of the uncoated carrier material by no greater than 20%, preferably no greater than 5%, in the wavelength range of 2.5 [mu]m to 50 [mu]m.

Description

Be used to absorb the optical effect multilayer system of solar energy

Technical field

The present invention relates to a kind of composite with carrier, said carrier is made up of aluminum or aluminum alloy as a rule.In the first embodiment, in the optical effect multilayer system of at least simultaneously coating at least five layers of composition to carrier.In second embodiment; Coat an optical effect layer for the carrier back side; This optical effect layer can the appropriate change uncoated the reflectivity of carrier material, thereby can utilize laser heat-transfer pipe to be joined on the composite with mode efficient more, that cost is lower.Can suitably select the optical parametric of this optical effect layer in addition, make it can significantly not reduce the high reflectance of metal carrier material in infrared wavelength range, thereby thermal radiation loss remained on minimum degree can be among being applied to solar thermal collector the time.So just can improve heat is conducted the efficient to thermal medium.Preferably two embodiments are mutually combined, improve heat is conducted the efficient to thermal medium.Preferably two embodiments are mutually combined.This composite is particularly suitable among the solar thermal collector.

Background technology

In solar thermal collector, need absorb the solar radiation (300～2500nm) and change it into heat of incident as far as possible.For the loss that infra-red radiation is caused is reduced to a minimum, according to Kirchhoff's law of radiation and conservation of energy condition, the reflectivity of material therefor in 2.5 μ m to 50 mum wavelength scopes must be high as far as possible.This is not only applicable to this one side that heat-absorbing material receives solar radiation, and is applicable to the back side.Therefore if will be used among the solar thermal collector, must use can satisfy the high reflectance requirement in 2.5 μ m to the 50 mum wavelength scopes equally on the two sides of material therefor.

The material that is used for solar thermal collector also is known as the selective solar absorbing material.It is known already that TiNOX by name has the composite of these optical characteristics, and in WO95/17533, this is described to some extent.The TiNOX material is that a kind of reflector/absorber file (for example can be consulted the article " Solar Energy, the State of the art " of Jeffrey Gordon, 2001ISES).Can the efficient absorption solar radiation but in the infra-red radiation scope as far as possible the absorbed layer of printing opacity be coated in 2.5 μ m to 50 mum wavelengths had on the surface of high reflectance very; Especially be coated on a kind of metal or its alloy of copper, aluminium, molybdenum, gold, silver, tantalum, Ni-V-Fe and so on, can realize above-mentioned optical characteristics.So just can realize very high reflectivity through the high reflecting surface of below.

Preferably use a kind of copper or aluminum metal carrier material as the high reflecting surface (T1) in the TiNOX composite, this material has very high reflectivity in 2.5 to 50 mum wavelength scopes.But point out also that in above-mentioned patent the mode that can use any one (non-optical effect) carrier material of above-mentioned a certain metal pair to carry out the coating processing produces high reflecting surface.Therefore carrier material itself or the high reflecting metal coating that is coated on the carrier material are exactly the part of optical multilayer system.

If use TiNOX, then be coated on the high reflecting surface (reflecting layer) ground floor (T2) just absorbed layer preferably by TiN _xO _yForm (wherein x, y=0.1～1.7).Top layer (T3) is an anti-reflecting layer, and this layer is made up of a kind of metal oxide, preferably by SiO ₂, ZrO ₂, HfO ₂, Al ₂O ₃Or Y ₂O ₃Form, can be used for the solar radiation reflectivity on the composite material surface is reduced to minimum level, thereby improve the solar radiative absorption rate in the composite.

Many other selectivity absorbing materials based on reflector/absorber file principle have been described in document.Absorbed layer is made up of a kind of stoichiometric proportion metallic compound of owing as a rule, or is made up of the cermet that metallic is distributed among the dielectric matrix.Except using the above-mentioned titanium oxynitrides the current use chromium oxide (CrO that recommends usually on the copper carrier _xBe to owe stoichiometric proportion between oxygen and the trivalent chromium) or use a kind of " cermet " of forming by the chromium particle in the chrome green of stoichiometric(al) as the light absorbing zone on the shady face, for example can consult C.E.Kennedy, Review of Mid-to High-Temperature Solar Selective Absorber Materials; NREL (National Renewable Energy Laboratory); Technical Report July 2002 and the document O.A.Panchenko et al.in Probl.At.Sei.Technol.Ser.:Plasma Phys. that wherein quotes, 132, (1999) 253 with in Int Conf.Coat.Glass; High-Perform.Coat.Transparent Syst.Large-Area High-Vol.Appl.; Pulker H.K.et al., Elsevier Science, Amsterdam; 1999, S.287.Also the someone discussed gradient layer under the prior art condition, for example can consult C.Nunes et al., Thin solid films 442 (2003) 173-178.People such as W.Graf have introduced a kind of gradient mixture of being made up of chromium oxide and chromium nitride in Journal ofNon-Crystalline Solids 218 (1997) 380-387, equally also with the cermet form it is splashed on the copper matrix.Developed this mixture, because almost can't realize graded oxidation chromium layer.Have responsive stable transition region between crome metal and the chromium oxide, very little working condition changes will cause metal deposition alternative metals oxide, and vice versa.Solution is that nitrogen is joined among the oxygen atmosphere, because the metering of the different chemical of nitride is very wideer than scope.In this publication, also discussed certainly " at Cr _xO _yIn contain the cermet of a small amount of CrN ", gradient is not described.This is enough to tolerate moisture and temperature, and this is to influence the solar thermal collector important environmental factor in service life.M.Kohl; M.Heck; S.Brunold; U.Frei; B.Carlsson; K.

described in " Advanced procedure for the assessment of the lifetime of solar absorber coatings " article that Solar Energy Materials & Solar Cells 84 (2004) 275-289 deliver and measured the standard test method in service life of selective solar absorbing material.

Yet the layer of owing stoichiometric proportion has following shortcoming: when solar thermal collector is worked; These layers meeting becomes awfully hot; Temperature may reach 230 ℃; Unsaturated then metallic atom will react with airborne oxygen, so these layers can be As time goes on and oxidation (for example can be consulted Holloway, P.H.; Shanker, K.; Pettit, R.B.; Sowell, R.R.: " Oxidation of electrodeposited black chrome selective solar absorber films "; Thin Solid Films, Vol.72, S.121-128, and 1980), absorbability will descend.Metallic atom (for example can be consulted P.H. among will being diffused into absorbed layer from the reflecting layer in addition; Shanker, K.; Alexander, GA.; De Sedas, L.:Oxidation and diffusion in black chrome selective solar absorber coatings, Thin Solid Films, Vol.177, S.95-105, and 1989), also can observe the oxidation in reflecting layer.Diffusion process within the absorbed layer also possibly cause gradient to reduce (for example can consult Christina Hildebrandt in addition; " Hochtemperaturstabile Absorberschichten f ü r linear konzentrierende solarthermische Kraftwerke " Dissertation 2009,

Stuttgart).These processes will cause the optical characteristics of composite change (degeneration) in average 20 years solar thermal collector length of life.

In addition for the function of solar thermal collector; Importantly give heat transfer medium with efficient release of the heat that is produced; Usually utilize suitable joint method will (mainly be processed) metal tube by copper, stainless steel or aluminium is fixed on the back side of material for this reason; Through these pipe a kind of suitable heat transfer mediums of pumping (mainly being water/ethylene glycol mixture or a kind of heat kerosene), this heat transfer medium arrives required acceptance point with heat delivery then.At this moment crucial being realized conductivity of heat as well as possible between material and pipe.Confirmed especially preferably to use method of laser welding (to consult " Laserlicht trifft Sonnenlicht " von Dr.Ulrich D ü rr; Mikroproduktion 3/2006; Carl Hanser Verlag M ü nchen; S.28) the aluminium heat-absorbing material is bonded on the pipe fitting, in most cases can uses the Nd-YAG pulse laser of optical maser wavelength as 1064nm.Because the reflectivity of undressed aluminium surface in this wave-length coverage is very high, will reflect the available emittance more than 95%, therefore have only little energy to can be used for welding process.The low flat laser beam incident angle β of use between 10 ° and 20 ° can be reduced at least 90% with the reflectivity of 1064nm wavelength, the incident condition that composite and pipe fitting is welded together referring to use laser shown in Figure 2.The reflectance spectrum on the aluminium surface of being untreated when being 10 ° shown in Figure 2 for vertical incidence angle and incidence angle.Reason from the production technology aspect can't continue to reduce incidence angle, is the spacing of 120mm because the pipe fitting on next door has at most usually, can hinder laser beam.Therefore need to use the very strong laser instrument of power.Intelligence is carried out work with very little pulse frequency in addition, thereby causes smaller production efficiency or dot density seldom.Dot density seldom can cause the conductivity of heat between baffle and the pipe fitting smaller, this efficient that all can reduce solar thermal collector in any case.

Summary of the invention

In order to overcome above-mentioned difficulties, the present invention provides and can separate or make up the solution that realizes.

Carrier material according to composite of the present invention is made up of aluminum or aluminum alloy.Also can replace use copper or stainless steel base material as the shady face layer system.

The layer system of composite shady face B below will at first be described with reference to figure 1.

Related is a kind of by at least 5 layers (3,4,5; 6; 7) the optical effect multilayer system of forming (9), top layer wherein (7) be have the following stated form, as the dielectric layer and/or the oxide skin(coating) of anti-reflecting layer, the bottom of optical effect system (3) is made up of a kind of metal or metal alloy; Has integrated reflectivity in the wave-length coverage between 2.5 to 50 μ m, preferred aluminium, copper, chromium, gold, silver, tantalum, nickel, vanadium, platinum, iron, titanium and/or molybdenum and alloy thereof greater than 80%.Preferred especially aluminium and copper, but molybdenum, nickel and silver also preferably selected for use.Usually this layer is called the reflecting layer.Between the bottom (3) of optical effect system and carrier material, can insert an intermediate layer (2), in order to the adhesive force that improves multilayer system and/or suppress metal in the carrier material and be diffused among the multilayer system.For example related can be to paint the adhesion layer that maybe can improve the adhesive force of metal level on metal base, if layer (3) fully combines with base material, then can save this layer.Intermediate layer (5) is the real absorbed layer of this system; Related is to consist of Me _rAl _sN _xO _yC _zOxygen and/or nitrogen and/or carbon owe the stoichiometric proportion metallic compound; Wherein Me is a kind of metal that is selected from the IV subgroup; For example titanium or chromium, coefficient r and s are represented the ratio (if s+r=2, then s can be the arbitrary value between 0 to 1.9) between this metal and the aluminium; Coefficient x, y and z represent to have non-stoichiometric in oxide, nitride and/or the carbide, and condition is that the x+y+z sum shows that the stoichiometric proportion between anion and the cation is not enough.Between layer (5) and the layer (7) is aluminium or oxidation saturated (stoichiometric proportion) metal oxide layer (6) that is selected from a kind of metal of IV or V or VI subgroup, for example Cr ₂O ₃Or Al ₂O ₃Between layer (5) and the layer (3) is a metal nitride and/or metal carbide layer (4), and related is nitride, carbonitride or the carbide that is selected from a kind of metal of IV or V or VI subgroup, for example CrN or TiC.The top layer of optical effect multilayer system (7) is a dielectric layer, and the refractive index of this dielectric layer preferably between 1.3 to 2.2, preferably includes especially and forms MeO between 1.3 to 2.4 _vN _w, coefficient v wherein, w represent stoichiometric proportion or the non-stoichiometric in oxide and the nitride.Can use silicon, zinc, tin, zirconium, hafnium, chromium, aluminium, yttrium or bismuth as metal, also can select to use fluoride.

Two layers that are positioned at layer (5) below and top can be protected it, can suppress above-described ageing process.The metal nitride or the carbide of lower floor (4) can be used as the barrier layer, diffuse out from reflecting layer (3) even from carrier material (1) in order to suppress metallic atom, also can be used as and prevent that the reflecting layer from suffering the protective layer of oxidative attack.The layer (6) of layer (5) top is an oxidation saturated (stoichiometric proportion) metal oxide layer, under temperature action, can not react with airborne oxygen, can be used as the protective layer that prevents that layer (5) from suffering oxidative attack.

Optical effect multilayer system according to the present invention can absorb the solar radiation more than 80% under AM 1.5 conditions, and in 2.5 μ m to 50 μ m infra-red radiation scopes, has the integrated reflectivity greater than 80%.

Therefore the multilayer system of being made up of at least 5 layers according to the present invention (9) is compared more anti-oxidant with the multilayer system that 3 layers are formed, heat endurance is better, can satisfy same optics requirement.

Said according to first-selected embodiment, that form absorbed layer 5 is especially composition CrO of a kind of titanium aluminium carboxyl nitride, a kind of nitrogen chromium oxide _xN _y, wherein x=1.0-1.4 and y=0.02-0.4, or a kind of chromium carboxyl nitride.

Shown in Figure 5 is reflectance spectrum according to two embodiments of multilayer system of the present invention.In one case, absorbed layer (5) is formula CrO _xN _yA kind of stoichiometric proportion chromium nitrogen oxide, wherein x=1.2-1.3 and y=0.1-0.2 of owing; Under another kind of situation formula Ti _rAl _sO _xN _yC _zA kind of titanium aluminium carboxyl nitride, r=1 wherein, s=1, x=1.2-1.4, y=0.02-0.1 and z=0.2-0.3 equally also are a kind of stoichiometric proportion compositions of owing.

Shady face A according to multilayer system of the present invention can keep not having coating, can select that also this one deck is carried out coating and handle.

According to a kind of embodiment that not only can make up use but also can independently realize of the present invention with the above-mentioned layer system of positive (B); The back side can have an optical effect layer; When the optics of certain wavelength X is injected with certain incidence angle; This one deck can be at 200nm to 10 μ m, preferably in 200 to 2500nm wave-length coverages, the reflectivity of the carrier material of uncoated is reduced at least 5%; And can be in 2.5 μ m to 50 mum wavelength scopes the integrated reflectivity of the carrier material of uncoated be reduced to be no more than 20%, especially be no more than 5%.

Adopt the back side of the composite that the present invention recommended, can significantly improve heat is conducted the efficient to flowing heat medium in the pipe.Optical effect layer through being coated on the back side reduces the surperficial reflectivity of aluminium, makes the laser emission energy lose seldom, can realize this effect.Shown in Figure 3 for scribbling 190nm thickness A l ₂O ₃The aluminium surface of layer is in the reflectance spectrum of incidence angle when being β=10 °.Can find out, under this useful especially situation, can the reflectivity of 1064nm wavelength be reduced to below 82%.Like this or can improve dot density, maybe can enhance productivity.Because optical effect layer according to the present invention has special characteristic, can or only not reduce the reflectivity in the thermal radiation range on a small quantity, thereby can be used for avoiding in the solar thermal collector thermal radiation loss.

In order to effectively reduce reflectivity as far as possible to used optical maser wavelength; The suitable layer thickness of selective optical active layer; Thereby make the folded light beam destructive interference, the condition that needs to satisfy is: in optical effect laminar surface institute's beam reflected and at first through the optical effect layer and then from producing the phase difference of the odd of π between the light beam of optical effect laminar surface ejaculation.

If wavelength is that the light beam of λ is with incidence angle α _i(α _i+ β=90 °) the directive composite (referring to Fig. 4, is used for explaining with incidence angle β or incidence angle α _i(α _i+ β=90 °) sketch map of directive composite and the laser beam light path that is reflected), this light beam will be at the optical effect laminar surface by partial reflection (r ₁) and part see through this layer, following between optical effect layer and alumina supporter material then at the interface equally by partial reflection (r ₂).A point institute beam reflected is the same with B point institute beam reflected all to have experienced phase shift, so folded light beam r ₁And r ₂Two phase shifts will offset.For at folded light beam r ₁And r ₂Wavefront between phase difference π appears, light beam r ₁The optical path length (AD) and the light beam r that sees through the optical effect layer of process ₂The difference of optical path length (ABC) of process be necessary for the odd of λ/2.

Can find out, among the C point is reflexed to optical effect again and through multiple internal reflection (r _n) this part light beam of penetrating from the optical effect laminar surface afterwards has and light beam r ₂The same phase place.Therefore only observe light beam r ₁And r ₂Just be enough to draw optimal layer thickness.

Draw two folded light beam r through following calculating formula ₁And r ₂Optical path difference Δ (n wherein ₀, n _g, n _tBe the refractive index of air, optical effect layer and mounting medium):

$\mathrm{\Δ}=n_g[\left(\stackrel{\‾}{\mathrm{AB}}\right)+\left(\stackrel{\‾}{\mathrm{BC}}\right)]-n_0\left(\stackrel{\‾}{\mathrm{AD}}\right)$

Wherein

$\left(\stackrel{\‾}{\mathrm{AB}}\right)=\left(\stackrel{\‾}{\mathrm{BC}}\right)=d/\cos {\mathrm{\α}}_t$

Draw

$\mathrm{\Δ}=\frac{2n_{g}d}{\cos {\mathrm{\α}}_t}-n_0\left(\stackrel{\‾}{\mathrm{AD}}\right)$

Wherein

$\left(\stackrel{\‾}{\mathrm{AD}}\right)=\left(\stackrel{\‾}{\mathrm{AC}}\right)\sin {\mathrm{\α}}_t$

Draw angle [alpha] through Snell laws of refraction _iAnd α _tRelational expression following:

$\left(\stackrel{\‾}{\mathrm{AD}}\right)=\left(\stackrel{\‾}{\mathrm{AC}}\right)\frac{n_g}{n_0}\sin {\mathrm{\α}}_t$

In addition

$\left(\stackrel{\‾}{\mathrm{AC}}\right)=2d\tan {\mathrm{\α}}_t$

Therefore can draw according to the triangular transformation relation of path difference:

Δ＝2n _gdcosα _t

Draw two light beam r through following calculating formula now ₁And r ₂Phase difference δ

$\mathrm{\δ}=\frac{2\mathrm{\π}}{\mathrm{\λ}}\mathrm{\Δ}=\frac{4\mathrm{\π}{n}_g}{\mathrm{\λ}}d\cos {\mathrm{\α}}_t$

If δ=π then draws the maximum reflection decay.

$\mathrm{\π}=\frac{4\mathrm{\π}{n}_g}{\mathrm{\λ}}d\cos {\mathrm{\α}}_t$

If resolve this formula and with angle [alpha] according to d _tReplace to incidence angle α _i, then can obtain the following relational expression of optical effect layer optimal layer thickness:

$d=\frac{\mathrm{\λ}}{4n_g}{(1-\frac{n_0^2}{n_g^2}{\sin }^2{\mathrm{\α}}_i)}^{-1/2}$

Utilize this formula can be directed against employed laser wavelength lambda and employed laser beam incident angle α respectively _iThe layer thickness d of (usually between 70 ° to 80 °) adjustment optical effect layer.Can be to concrete applicable cases adjustment composite, because corresponding laser beam wavelength is given value (greatly between 200nm to 10 μ m).

Can utilize Fresnel equation to calculate the maximum reflectivity that can reach and reduce amplitude.Utilize a kind of reflectance spectrum from the matrix method calculating chart 4 that Fresnel equation is derived, for example can consult E.Hecht " Optik ", Verlag Oldenburg 2001.

Can suitably design the optical effect layer (8) on the A face in addition; Make it can be used as the anticorrosive coat of used carrier material simultaneously; Thereby can prevent to reduce the reflex at the carrier material back side because of corrosion; Even composite is used among the solar thermal collector for a long time, can guarantee that also the loss that infra-red radiation causes keeps extremely low.

The material that is particularly preferred for layer (8) is the material that also can be used for front anti-reflecting layer (7), for example aluminium oxide or silica.The preferred especially mode coating alumina layer that the alumina supporter material is carried out electrochemical anodic oxidation that adopts.

Compare with the composite that is used for solar thermal collector up to now; Composite according to the present invention is characterised in that: optical effect layer (8) is coated on the A face of mounting medium; Laser capable of using makes heat-transfer pipe be bonded on the composite, and efficient is higher, and cost is lower.Can suitably select the optical parametric of this layer (8) in addition, make it can significantly not reduce the high reflectance of metal carrier material in infrared wavelength range, thereby thermal radiation loss remained on minimum degree can be among being applied to solar thermal collector the time.Suitable design level (8) makes its back side that can prevent metal corrosion, even composite is used among the solar thermal collector for a long time, reflectivity can not reduce significantly yet, thereby thermal radiation loss is remained on not half.(B) the optical effect multilayer system on the face has the extra high characteristics of temperature stability, because the saturated protective layer of employed chemistry is the part of optical effect intermediate system.

Can be according to conventional route production according to composite of the present invention.For example can use business-like PVD method to deposit, but also can use for example CVD or PECVD method according to absorbed layer of the present invention.Winding mechanism capable of using make sheet metal strip (carrier material) in vacuum chamber with constant speed through different PVD coating station, thereby can be progressively each layer of said multilayer system be coated on the B face of carrier material.

Can before coating operation, the package sheet metal strip be placed among the vacuum chamber, carry out the coating processing and afterwards it is retrieved (batch process); Or among through the vacuum air-locked valve system sheet metal strip being sent into vacuum from atmospheric environment, carry out coating and through second vacuum air-locked valve system it is sent into (air is to air technology) among the atmospheric environment again again after handling.

Sheet metal strip is preferred through one or more plasma for purification stations before coating, so that remove surperficial dirty (for example water, machine oil, grease, the oxide) of metal base, thereby guarantees the good adhesion of multilayer system.

If the PVD method then can be used for example magnetron sputtering, air-flow sputter, ion beam sputtering, electron beam evaporation, thermal evaporation or ARC method of evaporating.Can only use a kind of PVD method to come each layer of coated with multiple layer system.In most cases a kind of PVD method is particularly suitable for depositing material different, but also can use different PVD methods simultaneously.

In most cases use a kind of reactive PVD method to come deposition oxide, nitride and/or carbide.Above-mentioned a certain method capable of using is come plated metal, and oxygen and/or nitrogen and/or the gas that contains carbon is blown among the PVD chamber with defined flow velocity through a kind of gas distributing system, makes metal and required compound react.

Can be in accordance with known methods, or through window of web velocities, or control the layer thickness of each layer through the injecting power in each PVD coating station.Can be through diverse ways inspection, control deposition velocity.Mainly use bounce technique, elliptical polarization method, quartz crystal succusion or x-ray fluorescence method at industrial circle.

Can adopt above-described a kind of PVD (also comprising CVD and PECVD) method that the optical effect layer is coated on the A face of carrier material.The preferred especially mode coating alumina layer that aluminium sheet is carried out electrochemical anodic oxidation that adopts.

The specific embodiment

Embodiment:

Use 0.3 to 0.5mm thick aluminium sheet (aluminium 99.5%～99.8% purity) as carrier material, adopt electrochemical anodic oxidation technology that the thick alumina layer of 100 to 200nm (preferred especially 190nm) is coated on the aluminium sheet.Plate alumina layer for the A face and the B face of aluminium sheet.Alumina layer is formed optical effect layer 8 at the A face, forms intermediate layer 2 at the B face.

Then using the empty aluminum strip of the process electrochemical anodic oxidation being handled to blanking bar material coating apparatus of commercialization to carry out coating handles.(for example publisher Gerhard Kienel has just described this type of band coating apparatus in 1993 at the 5th 187-199 page or leaf of " vacuum coating " series of books of VDI publishing house publication).

Aluminum strip gets into via a plurality of band blocking valves among the vacuum chamber, then through a plurality of plasma for purification stations.Then guide band through a plurality of by blocking valve magnetron sputtering station spaced apart from each other.

The sputter layer of aluminum forms reflecting layer 3 in first sputter station.

In sputter station subsequently, adopt the mode of reactive sputtering chromium to form protective layer 4 at the condition deposit one deck CrN that quantitatively adds nitrogen.

The mode that in next sputter station, adopts reactive sputtering chromium is at the condition sinking arrears stoichiometric proportion CrO that quantitatively adds oxygen-nitrogen mixture _xN _yForm absorbed layer 5.

In the end adopt the condition deposit one deck Cr of the mode of reactive sputtering chromium in a sputter station at quantitative adding oxygen ₂O ₃Form protective layer 6.

These sputter procedure are all at 1e ^-3To 5e ^-3Accomplish in the mbar pressure limit.Use argon gas as sputter gas.

Band is through getting into after another blocking valve among the eb evaporation chambers, utilizes electron beam technology to make SiO here ₂Evaporation.Be blown into quantitative oxygen in the meantime, make operating pressure at 1e ^-4To 5e ^-4In the mbar scope.Here the SiO that applies ₂Layer is formed the anti-reflecting layer 7 of multilayer system.

Detect, regulate the layer thickness of each layer of multilayer system through ellipsometer.

Guide band to get among the atmospheric environment again then, and here its rolling is got up through multistage band blocking valve.

Claims (21)

1. as the composite of selective solar absorbing material, it comprises the carrier layer of being made up of aluminium, aluminium alloy, copper or stainless steel (1), wherein on a face (B) of said carrier layer, has following layer at least:

-by the reflecting layer (3) that metal or metal alloy is formed, have integrated reflectivity in its wave-length coverage between 2.5 and 50 μ m greater than 80%,

-measure the absorbed layer of forming than the metallic compound of not enough oxygen and/or nitrogen and/or carbon (5) by whole anion chemistry; Wherein said metal is selected from the combination of IV subgroup metal, chromium and IV subgroup metal and aluminium or the combination of chromium and aluminium; Wherein based on the total amount of metal; Aluminium content is maximum 95At.-%; Wherein said absorbed layer is positioned at top, said reflecting layer (3);-have stoichiometric proportion or non-stoichiometric composition, refractive index dielectric and/or oxide anti-reflecting layer (7) between 1.3 and 2.4, that be positioned at said absorbed layer (5) top; It is characterized in that, between said absorbed layer (5) and said reflecting layer (3), have the layer of forming by nitride, carbide or the carbonitride of the mixture of a kind of metal of IV, V or VI subgroup or two kinds or more kinds of metals (4), and between said absorbed layer (5) and said dielectric reflection layer (7) existence by having the optical activity layer (6) that metallic compound that stoichiometric proportion forms is formed.

2. according to the composite of claim 1, it is characterized in that, between said carrier layer (1) and said reflecting layer (3), have intermediate layer (2).

3. according to the composite of claim 1 or 2; It is characterized in that; Said reflecting layer (3) is made up of the metal that is selected from following group: the alloy of Al, Cu, Cr, Au, Ag, Ta, Ni, V, Pt, Fe, Ti and Mo and two kinds or more kinds of these metals, preferably form by Al or Cu.

4. according to the composite of one of aforementioned claim, it is characterized in that said layer (4) is chromium carbide, chromium nitride or carbon chromium nitride.

5. according to the composite of one of aforementioned claim, it is characterized in that said layer (5) has composition CrO _xC _yN _zOr Ti _rAl _sN _xO _yC _z, r+s=2 wherein, s=0 to 1.9, and select coefficient x, y and z to make the anion chemistry metering of metallic compound than not enough.

6. according to the composite of one of aforementioned claim, it is characterized in that said layer (6) is the metal of IV, V or VI subgroup or the metal oxide layer of aluminium.

7. according to the composite of one of aforementioned claim, it is characterized in that said layer (7) is made up of oxide, nitride or the nitrogen oxide of metal or silicon.

8. according to the composite of one of aforementioned claim, it is characterized in that said layer (7) is the outermost layer on said.

9. be used as the composite of selective solar absorbing material; It comprises the carrier layer of being made up of aluminum or aluminum alloy (1); Wherein on a face (A) of said carrier layer, has optical effect layer (8); Said optical effect layer between 200nm and the 10 μ m, preferably 200 and 2500nm between wave-length coverage in the situation of specific wavelength λ under when injecting, make the reflectivity of the carrier material of uncoated reduce at least 5% with specific incidence angle; And make the reflectivity of the carrier material of uncoated reduce to be no more than 20% in the wave-length coverage between 2.5 μ m and 50 μ m, preferably be no more than 5%.

10. according to the composite of claim 9, the layer thickness of wherein said layer (8) meets following formula

$d=\frac{\mathrm{\λ}}{4n_g}{(1-\frac{n_0^2}{n_g^2}{\sin }^2{\mathrm{\α}}_i)}^{-1/2},$

Wherein λ is illustrated between 200nm and the 10 μ m, and α _iIt is the angle between 0 ° and 80 °.

11. according to the composite of claim 9 or 10, wherein λ=1064nm.

12. according to the composite of claim 10 or 11, wherein α _iIt is the angle between 70 ° and 80 °.

13. the composite according to one of claim 9 to 12 is characterized in that, said layer (8) is made up of oxide, nitride or the nitrogen oxide of metal especially aluminium or silicon.

14. the composite according to one of claim 9 to 13 is characterized in that, on the face (B) of said (A) of said carrier layer dorsad, has following layer at least:

-by the reflecting layer (3) that metal or metal alloy is formed, have integrated reflectivity in its wave-length coverage between 2.5 and 50 μ m greater than 80%,

-measure the absorbed layer of forming than the metallic compound of not enough oxygen and/or nitrogen and/or carbon (5) by whole anion chemistry; Wherein said metal is selected from the combination of IV subgroup metal, chromium and IV subgroup metal and aluminium or the combination of chromium and aluminium; Wherein based on the total amount of metal; Aluminium content is maximum 95At.-%, and wherein said absorbed layer is positioned at top, said reflecting layer (3)

-have stoichiometric proportion or non-stoichiometric composition, refractive index dielectric and/or oxide anti-reflecting layer (7) between 1.3 and 2.4, that be positioned at said absorbed layer (5) top; It is characterized in that; Between said absorbed layer (5) and said reflecting layer (3), have the layer of forming by nitride, carbide or the carbonitride of the mixture of a kind of metal of IV, V or VI subgroup or two kinds or more kinds of metals (4), and between said absorbed layer (5) and said dielectric reflection layer (7) existence by having the optical activity layer (6) that metallic compound that stoichiometric proportion forms is formed.

15. the composite according to claim 14 is characterized in that, between said carrier layer (1) and said reflecting layer (3), has intermediate layer (2).

16. composite according to claim 14 or 15; It is characterized in that; Said reflecting layer (3) is made up of the metal that is selected from following group: the alloy of Al, Cu, Cr, Au, Ag, Ta, Ni, V, Pt, Fe, Ti and Mo and two kinds or more kinds of these metals, preferably form by Al or Cu.

17. the composite according to one of claim 14 to 16 is characterized in that, said layer (4) is chromium carbide, chromium nitride or carbon chromium nitride.

18. the composite according to one of claim 14 to 17 is characterized in that, said layer (5) has composition CrO _xC _yN _zOr Ti _rAl _sN _xO _yC _z, r+s=2 wherein, s=0 to 1.9, and select coefficient x, y and z to make the anion chemistry metering of metallic compound than not enough.

19. the composite according to one of claim 14 to 18 is characterized in that, said layer (6) is the metal of IV, V or VI subgroup or the metal oxide layer of aluminium.

20. the composite according to one of claim 14 to 19 is characterized in that, said layer (7) is made up of oxide, nitride or the nitrogen oxide of metal or silicon.

21. the composite according to one of claim 14 to 20 is characterized in that, said layer (7) is the outermost layer on said.

Images